File tool handle



Aug. 12, 1958 E; GRANBERG FILE TOOL HANDLE Filed llarch 25, 1957 INVENTOR. ELOF 6R4 NBERG HIS ATTORNEYS ited States Patent FILE TOOL HANDLE Elof Granberg, Richmond, Calif.

Application March 25, 1957, Serial No. 648,335

6 Claims. (31. 29-80) My invention relates to a tool handle and more particularly to a handle for tools such as files or the like which normally terminate at the handle end in a long tapered shank to which a handle may, if desired, be applied.

Among the objects of my invention are:

(1) To provide a novel and improved handle for tools such as files or the like;

(2) To provide a novel and improved handle for tools such as files or the like, which may be manually applied and removed with very little difficulty;

(3) To provide a novel and improved handle for tools such as files or the like, which is of exceedingly simple construction and may be manufactured economically;

(4) To provide a novel and improved handle for tools such as files or the like which is very comfortable to the user and permits more effective control over the move ments of the tool;

(5) To provide a novel and improved handle for tools such as files or the like, which is applicable to such tools within a wide range of shank sizes.

Additional objects of my invention will be brought out in the following description of a preferred embodiment of the same taken in conjunction with the accompanying drawings wherein,

Figure l is a view depicting my improved handle as applied to a tool such as a file;

Figure 2 is a view in section through the handle of Figure 1.

Referring to the drawings for details of my invention in its preferred form, the handle 1 is preferably in the form of a ball or sphere 3 having an axial or diametrical recess 5 therein, the recess being conical in shape and extending approximate to or through the surface opposite the entrance to said recess. The surface of the recess, particularly the inner portion thereof, is covered with means for gripping the shank 7 of a tool 9 when inserted therein. Such gripping means 10 may be a thread of hard material such as metal, and may take the form of a steel wire wound on a conical spiral to provide a complementary fit in the recess in which the spirally wound wire is fixed against movement relative to the ball in any suitable manner.

"One manner of accomplishing this is to form the ball of moldable material such as plastic, and molding the wire therein as the ball is formed, or the wire may be molded into an insert 11 of plastic or the like, which may thereafter be inserted and glued into the ball or otherwise affixed therein. In this latter case, the ball need not be of plastic material, but may be of wood or any other material suitable for a handle.

In utilizing the handle for its intended purpose, it is applied to the shank of the tool and twisted thereon to the point of causing the shank to bind with one or more of the threads, the particular threads and the number of them which engage the shank being determined largely by the angle of the shank. When so applied, the handle when sufficiently small, will fit in the palm of the hand 2,846,755 'Patented Aug. 12, 1958 2 and by reason of the shape and size of the handle, the fingers of the hand may not only readily grasp the tool proper, but the tool may be grasped closer to the functioning portion of the tool, thus giving the operator a more effective control over the movements of the tool.

Pressure applied to a handle during use of a tool such as a file, for example, will have a component of pressure along the axis of the tool to impart forward motion thereto across the work, and a lateral component to hold the tool in pressure contact with the work during such forward motion. I

Inasmuch as the handle of the present invention is so constructed that the shank binds with the threads in the immediate region where the manual pressure is applied during such use of the tool, any such lateral component of pressure will pass either directly through the contacting area of the shank or so close to it that no effective moment arm will exist which might tend to break the handle from its point of anchorage to the tool shank. Under the circumstances, only a minimum area of bind, such as may be provided by only one or two threads, is :all that is necessary to enable the handle to be effectively retained on the shank during use of the tool. The significance of this lies in the fact that a handle may be effectively anchored to shanks varying widely as to their angle of taper.

By making the thread of steel wire, it will tend to cut its own thread into the shank of the tool, if the metal of the shank is of a softer material, but in any event, a tight frictional grip of the thread upon the shank will serve to hold the handle thereon.

Should it be desirable to utilize the handle for another tool, the handle may be readily and conveniently removed from the shank upon which it had been aifixed, and then applied to the other tool merely by threading the same thereon under longitudinal applied pressure.

From the fore-going description of my invention in its preferred form, it will be apparent that the same fulfills all the objects of my invention, and while 1 have disclosed the same in its preferred form, the handle, as illustrated and described, is subject to alteration and modification without departing from the underlying principles involved, and I accordingly do not desire to be limited in my protection to the specific details illustrated and described except as may be necessitated by the appended claims.

I claim:

1. A manually applicable and removable handle for tools such as files or the like having a smooth tapered shank, comprising a unit knob having an axial recess and means extending into said recess on a taper and terminating in proximity to the surface of said knob opposite the entrance to said recess, said means being adapted to automatically grip such shank during rotational insertion of such shank into said recess.

2. A manually applicable and removable handle for tools such as files or the like having a smooth tapered shank, comprising a substantially spherical knob having an axial recess and a thread of metal extending into said recess on a taper and terminating in proximity to the surface of said knob opposite the entrance to said recess, said thread being adapted to automatically grip such shank during rotational insertion of such shank into said recess.

3. A manually applicable and removable handle for tools such as files or the like having a smooth tapered shank, comprising a substantially spherical knob having an axial recess and a spiral thread of metal extending into said recess on a taper and terminating in proximity to the surface of said knob opposite the entrance to said recess, said spiral thread of metal being adapted to automatically grip such shank during rotational insertion of such shank into said recess.

4. A manually applicable and removable handle for tools such as files or the like having a smooth tapered shank, comprising a knob having a conical recess therein and means along the surface of said recess and terminating in proximity to the surface of said knob opposite the entrance to said recess for automatically gripping such shank during rotational insertion of such shank therein.

5. A manually applicable and removable handle for tools such as files or the like having a smooth tapered shank, comprising a knob having a conical recess therein and a spiral thread along the surface of said recess and terminating in proximity to the surface of said knob opposite the entrance to said recess for automatically gripping such shank during rotational insertion of such shank therein.

6. A manually applicable and removable handle for tools such as files or the like having a smooth tapered shank, comprising a substantially spherical knob having a conical recess therein and a spiral Wound steel Wire along the surface of said recess and terminating in proximity to the surface of said knob opposite the entrance to said recess for automatically gripping such shank during rotational insertion of such shank therein.

References Cited in the file of this patent UNITED STATES PATENTS 2,018,376 McMenamin Oct. 22, 1935 2,574,330 Judd Nov. 6, 1951 2,721,375 M-alm Oct. 25, 1955 FOREIGN PATENTS 628,911 Great Britain Sept. 7, 1949 

